Programming Language = C#
You are given a 2D matrix of dimension and a positive integer . You have to rotate the matrix times and print the resultant matrix. Rotation should be in anti-clockwise direction.
Rotation of a matrix is represented by the following figure. Note that in one rotation, you have to shift elements by one step only.
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Solution Matrix Layer Rotation
1) Get the number of ROW and COLUMN
2) Get the number of Loop
3) Get the number of Rotation based on the ROW, COLUMN and R
4) Start Clockwise Rotation – Move First Row, Right Column, Move Last Row, Left Column
5) Get the final Matrix
static void matrixRotation(List<List<int>> matrix, int r)
{
int ROW = matrix.Count;
int COLUMN = ((List<int>)matrix[0]).Count;
int numLoop = ROW < COLUMN ? ROW / 2 : COLUMN / 2;
for (int i = 0; i < numLoop; i++)
{
int numRotations = r % (2 * (ROW + COLUMN – 4 * i) – 4);
for (int rotation = 0; rotation < numRotations; rotation++)
{
//clockwise
for (int j = i; j < COLUMN – i – 1; j++)
{
int temp = matrix[i][j];
matrix[i][j] = matrix[i][j + 1];
matrix[i][j + 1] = temp;
}
// Rotate right column
for (int j = i; j < ROW – i – 1; j++)
{
int temp = matrix[j][COLUMN – i – 1];
matrix[j][COLUMN – i – 1] = matrix[j + 1][COLUMN – i – 1];
matrix[j + 1][COLUMN – i – 1] = temp;
}
// Rotate bottom row
for (int j = COLUMN – i – 1; j > i; j–)
{
int temp = matrix[ROW – i – 1][j];
matrix[ROW – i – 1][j] = matrix[ROW – i – 1][j – 1];
matrix[ROW – i – 1][j – 1] = temp;
}
// Rotate left column
for (int j = ROW – i – 1; j > i + 1; j–)
{
int temp = matrix[j][i];
matrix[j][i] = matrix[j – 1][i];
matrix[j – 1][i] = temp;
}
}
}
// Output final matrix
for (int i = 0; i < ROW; i++)
{
for (int j = 0; j < COLUMN; j++)
{
Console.Write(“{0} “, matrix[i][j]);
}
Console.WriteLine(“”);
}
}
Happy Programming!!
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